This invention relates to a wound dressing package and more particularly to sterile packaging for a wound dressing that is to be mixed and dispensed from a single container.
Numerous packages have been proposed for mixing and dispensing pharmaceutical products. For example, patent U.S. Pat. No. 5,089,606 describes a hydrogel foam which is mixed and dispensed from two parallel cylindrical syringes which force two separate liquid solutions through a mixing tube that contains a helical mixing blade for mixing the solutions together. The syringes and mixer are relatively expensive, complicated in construction and sub-ject to malfunction. In addition, they are wasteful because a certain amount of the product will remain in the mixer. By contrast, the present invention has as its general object the provision of an improved package and dispensing system in which syringes are not required and wherein a single container is used for storing, mixing and dispensing a pharmaceutical product.
U.S. Pat. No. 2,756,874 describes a compartmented bag and package for mixing two kinds of paste materials, e.g., dental paste, both of which are in fluid state. The paste formulations are placed in compartments that are separated by means of a removable clamp. The clamp, besides adding expense to the package because of the extra parts required, also adds extra assembly steps for forming the package and complicates mixing because one must become familiar with how to remove the clamp. By contrast, an object of the present invention is to reduce the cost of the package by eliminating the need for a clamp and yet reliably maintain constituents separate from one another.
The present invention has a variety of uses but is particularly beneficial for use with topical pharmaceutical products that are to be applied to the skin such as wound dressing that may, for example, contain water and a natural or synthetic hydrocolloid in particulate form. In order to provide outstanding shelf-life properties, it is an object to maintain liquid and solid pharmaceutical components separate from one another or to maintain at least some of the solid components separate from the water contained in the formulation.
The compositions described in U.S. Pat. No. 2,756,874 contain water in both compartments. This will usually reduce shelf life. In many products, and particularly pharmaceutical products, spoilage is of critical importance. Naturally, anything that tends to degrade the product prior to use could reduce its effectiveness which is usually unacceptable. To maintain aqueous and non-aqueous components separate from one another requires an effective barrier that will reliably prevent contact between them. Even a small leak can drastically reduce the shelf-life of the product. However, the more reliable the barrier that is provided, the more difficult it will be to remove the barrier to enable the components to be mixed. Accordingly, it is an important object to find a way of providing a package containing water or an aqueous solution, a separate dry pharmaceutical product, and a barrier between them that is reliable enough to prevent any mixing of the water with the dry constituents but which is still capable of being opened easily at ambient temperature using manual pressure.
Another form of multi-compartmented medicament container is described in U.S. Pat. No. 4,550,825. However, the construction is complicated by the need for a relatively expensive package having a cylinder and plunger of a special design. A major objective of the present invention is to provide reliable separation of liquid and solid components over extended periods with a provision for mixing them just before use while at the same time eliminating the need for moving mechanical parts.
These and other more detailed and specific objects of the invention will be apparent in view of the following specification which illustrates by way of example but a few of the various forms of the present invention that will be apparent to those skilled in the art within the scope of the appended claims.
The invention provides a mixing and dispensing pouch for a to be applied to the body of a patient. The mixing and dispensing pouch comprises a container body formed from flexible sheet material including a pair of superimposed sheets that are connected together at their edges. A transversely extending pressure-rupturable seal is located between the superimposed sheets and extends from one edge of the package to the other. The pressure-rupturable seal can be forced open manually solely by mechanical pressure applied from the exterior of the package at ambient temperature by pressing on the liquid-containing portion of the package with the hands to substantially increase the hydrostatic pressure in the liquid-containing portion, causing the liquid to spurt through the rupturable seal and mix with the dry constituents contained in the second compartment. If required, additional kneading of the package with the hands will mix the liquid and solid components to prepare the resulting composition for use as soon as it is expelled from the package. The package can contain weak areas, e.g., notches to facilitate tearing the package open manually and, if desired, can include a pour spout having a frangible portion that can be removed to open the spout for expelling the contents thereof through the spout by applying manual pressure to the walls of the package.